The addition of insulation to a cylindrical surface such as a wire, may increase the rate of heat dissipation to the surroundings.
(a) For a No. 10 wire (0.26 cm in diameter), what is the thickness of rubber insulation (k=0.16 W/mK) that will maximize the rate of heat loss if the heat transfer coefficient is
10 W/m²K ?
(b) If the current-carrying capacity of this wire is considered to be limited by the insulation temperature, what percent increase in capacity is realized by addition of the insulation? State your assumptions.